8442

LVDS Frequency Synthesizer

The 8442 is a general purpose, dual output Crystal-to-Differential LVDS High Frequency Synthesizer. The 8442 has a selectable TEST_CLK or crystal input. The TEST_CLK input accepts LVCMOS or LVTTL input levels and translates them to LVDS levels. The VCO operates at a frequency range of 250MHz to 700MHz. The VCO frequency is programmed in steps equal to the value of the input reference or crystal frequency. The VCO and output frequency can be programmed using the serial or parallel interface to the configuration logic. The low phase noise characteristics of the 8442 makes it an ideal clock source for Gigabit Ethernet and Sonet applications.

Features

Dual differential LVDS outputs

Selectable crystal oscillator interface or

LVCMOS/LVTTL TEST_CLK

Output frequency range: 31.25MHz to 700MHz

Crystal input frequency range: 10MHz to 25MHz

VCO range: 250MHz to 700MHz

Parallel or serial interface for programming counter and output dividers